Sharp statements of Turkish President Recep Tayyip Erdogan against certain EU countries prove that there is no place for Turkey in the European Union, Czech President Milos Zeman said on Wednesday.

Relations between the European Union and Turkey worsened after the cancellation of Turkish politicians’ public appearances in Austria, Germany and the Netherlands by their respective regions’ authorities, ahead of Turkey’s national referendum on constitutional reform. The referendum is slated to greatly expand the executive powers of Erdogan, who strongly criticized the EU for banning pro-referendum rallies and compared respective European governments to Nazis. His statements led to appearance of cartoons showing Europe as the land of Nazis.

“Such a way of communication is partly unfortunate and only proves my long-standing belief that there is no place for Turkey in the European Union,” Zeman told reporters.

Commenting on Erdogan’s remarks that Europe will no longer be able to influence Turkey using the country’s possible entry into the European Union, Zeman said that there was only one card Erdogan could use against the EU.

“My opinion, and it may be quite cynical, is that the only card Erdogan has to play against the European Union is called ‘three million of migrants and opening of the Balkan route’ with all the consequences it could lead to. But as soon as he lets go of this card, he will have nothing to play with,” Zeman stated, explaining that Erdogan will not be able to “blackmail the EU with financial demands or visa-free relations.”

Turkey signed an association agreement with the then-European Community in 1963, submitting a membership application in 1987. Negotiations concerning the country’s membership in the European Union began in 2005. On November 24, 2016, European lawmakers voted in favor of freezing EU accession talks with Turkey until it lifts restrictive measures in the country that were introduced after the failed coup in July.

On March 18, Turkish Foreign Minister Mevlut Cavusoglu urged the European Union to implement a visa liberalization deal, saying that otherwise all other agreements between Ankara and Brussels, including the March 2016 refugee deal, could not be fulfilled. According to the deal, Ankara pledged to take back all undocumented migrants who come ashore in Greece if EU countries receive Syrian refugees resettled from Turkish camps on a one-for-one basis.